For presenting information to a human user a graphical presentation is often preferred. Thus, graphical interfaces are used by, for example, computers to present information.
In the field of computer human interface, particularly as it relates to the images on a computer video display and the user's interaction with that display, the display may be two dimensional (2D), or three dimensional (3D), or the display may be in a three dimensional (3D) environment which may be displayed on a two dimensional (2D) screen.
In a 2D user interface positions of interface elements are often defined in terms of pixel positions on a user interface, such as a display monitor. This is a natural way of working with positioning, and may be straight forward if pixels are of uniform size and shape.
In a 3D display system bitmaps may be displayed as texturemaps that are stretched onto polygons in 3D space. If a computer program needs to find the position of a pixel or in some other way act based on the position of a pixel on a texturemap the program may need to know where the texturemap pixel is located. Further, because of effects related to stretching, the texturemap pixel may be stretched or warped. This may present a problem.